Device having a helical element and an adjustable contactor therefor



June 11, 1968 A. J. LOMBARDI 3,388,364

DEVICE HAVING A HELICAL ELEMENT AND AN ADJUSTABLE CONTACTOR THEREFOR 3Sheets-Sheet l Filed Sept. 12, 1966 um 6E mm 6E INVENTOR.

ANTHONY J. LOMBARDI GENT June11,l968 AHLLQMBARDI 3388364 DEVICE HAVING AHELICAL ELEMENT AND AN ADJUSTABLE CONTACTOR THEREFOR Filed Sept. 12,1966 3 Sheets-5heet 2 AFC/ BRAKWG MEANS I l Q & I i lnnzaazzl DRIVEMEANS FIG.5

INVENTOR.

ANTHONYJ.LOMBARDI AGENT A. J. LOMBARDI DEVICE HAVING A HELICAL ELEMENTAND AN ADJUSTABLE CONTACTOR THEREFOR June 11, 1968 5 Sheets-Sheet 5Filed Sept. 12, 1966 INVENTOR ANTHONY J. LOMBARDI United States Patent 3388,364 DEVICE HAVENG AHELICAL ELEMENT AND AN ADJUSTABLE CONTACTORTHEREFOR Anthony J. Lombardi, Wyckoif, N..l., assignor to InternationalTelephone and Telegraph Corporation, Nutley,

Filed Sept. 12, 1966, Ser. No. 573,865 9 Claims. (Cl. 338-443) ABSTRACT0F THE DISCLQSURE A device is provided for use with a helical elementcomprising means which selectively ellcct contact engagement with turnsof the helical element and which withhold contact engagement duringadjustment relative to the helical element.

This invention relates to devices having a helical element and anadjustable contactor therefor, and more particularly to such devices asradiation, inductance and resistance coils having means for selectivelyeffecting contact engagement and for withholding contact engagement ofthe contactor during adjustment relative to turns of the.

helical element.

Heretofore contact devices have been proposed in which the turns of ahelical element serve as threads to advance the contactor along thesuccessive turns until the selected turn is in contact. Such knowndevices have incorporated means designed to insure continuous, positivecontact during the traverse of the element because in every helicalelement there is some departure in the turns from a true helix.Accordingly, the contacting device must provide for such deviations andmaintain contact at all times. As applied to an electrical conductor ofa radiation, inductance or resistance coil this would be important fromthe standpoint of preventing undue heating and galling or wear of theconductor and contactor during timing. If a poor electrical contact ispresent, arcing and burning effects may arise which would seriouslydamage or abrade the conductor turns or the contactor and thereby renderdifficult or prevent subsequent selective adjustment or contactortraversal of the turns. In the past it has been proposed to bias rollingor sliding contactors outwardly against the inner surface of the turnsto insure good contact and also to provide for irregularities in thecurvature of the turns. Yet, with fatigue of the contactor metal, oroccasionally recurring relaxation of the biasing means, uneven contactswill occur. In electrical applications this causes undue heating andresults in the aforementioned arcing and abrading. Especially is this sowhere high currents are involved.

It is an object of the present invention, to provide a contact device,for use with a helical element, having means for selectively effectingcontact engagement with turns of the helical element and for withholdingcontact engagement during adjustment relative the helical element.

It is the further object of the present invention to provide a contactdevice with means which effect a smooth adjustment of the device alongthe length of a helical element via the turns thereof and selectivelymakes and breaks contact with helical turns as may be desired.

A feature of the invention is the use of camming means to coact withslidable contactors of the contact device disposed centrally of thehelical turns of the element to make and break contact engagement withany selected turn.

The above mentioned and other features and objects of this inventionwill become more apparent by reference to the following descriptiontaken in conjunction with the accompanying drawings, in which:

FIG. 1 is a cross-sectional view of one embodiment of the invention;

3,388,364 Patented June 11, 1968 FIG. 2 is an interior plan view of thecontact device taken along line 2-2 of FIG. 1.

FIGS. 2A, 2B, and 2C illustrate different embodiments of contactorsusable with the contact device of FIG. 2;

FIG. 3 is a cross-sectional view of another embodiment of the inventionshowing a modified arrangement for actuation of contactors;

FIG. 4 is an interior plan view of a contact device taken along line 44of FIG. 3;

FIG. 5 is a cross-sectional view of the contact device of FIG. 4 takenalong line 55;

FIG. 6 is a cross-sectional view of another embodiment of the inventionshowing another modification of the arrangement for actuation of thecontactors;

FIG. 7 is an interior plan view of an inertially actuated contact deviceused in the embodiment of FIG. .4; and

FIG. 8 is a view of the contact device of FIG. 7 in a dynamic positionshowing the inertial lag of the device with respect to the camshaft.

Referring to the drawings, FIGURE 1 represents the helical element 1having a plurality of turns 2 with an internal contact device 3. Thecontact device 3, of plastic or other non-conductive material, slidesalong drive rods 4 and a camshaft 5 substantially octagonal incross-section, when traversing the length of the element 1. The rods 4are mounted in a hub 6 in which an actuator shaft 7, slidably joined toone end of the camshaft, is centrally located. Rigidly fixed to the hub6 is a spur gear 8 which meshes with gear 9. The actuator shaft 7 isslidably mounted in the hub 6, and an extended, smaller, hexagonalextension thereof 7 protrudes, slidably, into a hexagonal hollow 5' ofcamshaft 5. Between an internal shoulder 7" of the hub 6 and an externalshoulder 7 of the actuator shaft 7 is positioned a spring .10. Spring 10urges the actuator shaft 7 away from the hub 6 and against the end ofcamshaft 5. The actuator shaft 7 has a dog-leg slot 11 in one side Whereit is coaxial with the hub 6. A dowelpin 12, extending from the hub 6 inwhich it is secured, extends through slot 11. Thus, actuator shaft 7,and the hexagonal extension 7 extending therefrom, can slide within hub6, along the axis thereof, pin 12 and slot 11 slidably interacting toorient and limit the total axial and rotary displacements of actuatorshaft 7. The end of the actuator shaft 7 opposite the camshaft 5 housesradial bearings 13. Mounted within these bearings is a short shaft 14.Bearing block 15 receives one end of shaft 14, and both are securedtogether by pin 54. To bearing block 15 one end of a lever 16 isslidably pinned by dowel pin 17. The other end of lever 16 is slidablyjoined to the rotary means 18 via dowel pin 19. Lever 16 is pivotallymounted in the center at point 20. Drive means 21 and braking means 22provide input power and control to the power train of gears 8 and 9. Endplate 23 receives and secures the ends of drive rods 4. End cap 24 andplate 23 provide bearing apertures 25, in the center of each, in whichcamshaft 5 can freely rotate. Base cap 26 provides a bearing aperture 27in which hub 6 can rotate freely. Covering 28, in which turns 2 aredisposed, provides a non-metallic cylinder which, with caps 24 and 26,protects the turns from adverse environments and permits RF radiation.

Clamp 29 and wire lead 30 provide a coil connection for I electricalapplications of the helical element 1. Snap ring 55 sits in an annularrecess in actuator shaft 7, between bearings 13, and snap rings 55 sitin annular recesses on short shaft 14 at either ends thereof to securethe bearings 13. Snap rings 55 and 56 position the bearings 13 on shaft14 and insure that, with an axial displacement of shaft 14, actuatorshaft 7 will also be displaced therewith.

The contact device 3 is shown in greater detail in'FIG- URE 2 where aninternal plan view thereof is presented. There a plurality of contactors31 of electrically-conductive material is shown slidably mounted inradial slots 53 in the contact device. The contact device 3 also has anannular groove 59 formed in the outer edge to receive a circular spring32. Spring 32 is nested in recesses 60 formed in one surface of thecontactors 31; the ends .61 of the spring are parted but are constantlybeing urged toward tangency. This urging causes contactors 31 to restagainst camshaft 5. The camshaft is shown in abutting relationship tothe contactors 31. The drive rods 4 are also shown in cross-sectionthrough the contact device.

FIGS. 2A, 2B, and 2C show the contactor 31, and alternate embodiments,contactors 31' and 31", respectively, usable in the contact device 3.Contactor 31 has a pair of resilient, arcuate-ended fingers 4-5 and asecured to a body 46. The fingers are so formed at the ends thereof, andare sufiiciently resilient, to part slightly and present a concavecontacting face to turn 2 upon being urged thereagainst. Contactors 3.1and 31" have pro-formed concave faces at the ends 47 and 43 thereof andare resiliently mated to the bodies 49 and 50. Contactor 31' has aspring 51 Which provides resilient structural mating between end 47 andbody 49, and an electrically-conductive filament 52 to provide forcontinuity therebetween. Contactor 31", however, has anelectrically-conductive spring member 53 to provide both resilientstructural mating and electrical continuity.

At the outset, as shown in FIGURES 1 and 2, the device withholdsshorting contact between contactors 31 and turns 2 of helical element 1.Camshaft 5 must be rotated to move contact device 3 to that axial pointalong helical element 1 where it is desired to make conductive contact.Then, contact device 3 must be braked against further movement, relativeto the turns 2, and contactors 31 must be put into contact engagementwith the selected turn 2. This is done by causing camshaft 5 to executea slight rotary motion. This small rotation causes the cam surface 57 ofcamshaft 5 to push against the inner ends of contactors 31 and move themradially outward into contact with turn 2.

In more detail, the operation is as follows: Drive means 21 impart powervia gears 9 and 8 to hub 6. Hub 6 rotates and turns drive rods 4 andactuator shaft 7, together with the hexagonal extension 7'. Hexagonalextension 7' nested in hexagonal hollow 5' causes camshaft 5 to rotatetherewith. Contact device 3, slidably mounted on the rods 4 and camshaft5, and helically mating with the turns 2 of the element 1, is caused torevolve within and along the turns 2. Bearings 13 allow the actuatorshaft 7 to turn, with the camshaft 5 and hub 6, on short shaft .14 andallow the bearing block 15 to remain stationary. When the contact device3 has traversed the turns 2 of the element 1 to a point where it isdesired that contact be made, the camshaft 5 is actuated. To accomplishthis, braking means 22 are engaged to halt the input drive and to holdthe contact device at the desired point. Rotary means 18 are actuated topivot lever 16 and to withdraw hexagonal extension 7 from camshaft 5.With the pivoting of lever 16, actuator shaft 7 moves longitudinally,withdraws hexagonal extension 7', and turns slightly, as dowel-pin 12and slot 11 interact. Camshaft 5 turns with actuator shaft 7 andhexagonal extension 7' and, as the contact device 3 is held againstrotation by braking means 22, cam surfaces 57 cause contactors 31 toslide outward into contact with the turn 2 of the element 1.

Upon reverse actuation of rotary means 18, spring 10 returns camshaft 5to its inoperative position. Thus, springs 32 cause contactors 31 toslide inward to interrupt the contact. Rotary means 18 can bemechanically operated by a hand or foot-lever or any one of several wellknown arrangements.

FIGURE 3 illustrates a different embodiment of the invention, where thecamshaft 5" has a keyway 62 and a hexagonal hollow 5. An actuator shaft63, slidably positioned within hub 6, has a hexagonal extension 7'protruding therefrom which is received in hexagonal hollow 5. Thisembodiment has the same dog-leg slot 11 and dowel-pin 12 arrangement, asin the embodiment of FIG. 1, to crank the camshaft 5" into operation.However, the camming arrangement and the motive means are different.Actuator shaft 63 is retracted from hub 6 and camshaft 5" by solenoid 64and compression spring 65. When drive means 21 are actuated, solenoid 64is energized and causes actuator shaft 63 to retract to the position Ias shown. Snap ring 66 on actuator shaft 63 limits the extent ofretraction. Keyway 62 receives a key 37 which is fixed within contactdevice 3. Key 37 is freely slidable in the keyway 62. Within contactdevice 3 is cam sleeve 33 which has a transverse slot 67 in which key 37is secured. Cam sleeve 38 has external cam surfaces 57' and is rotatablewithin contact device 3. Snap rings 68 in either sides of contact device3 retain cam sleeve 38 centrally of the contact device 3.

In this embodiment, drive means 21 and solenoid 64 are energized tointerrupt shorting contact and to move contact device 3. Drive means 21rotates gears 9 and 8, hub 6 to which gear 3 is press fit, drive rods 4,and contact device 3. Rotation of device 3 causes cam sleeve 38 torotate therewith. The key 37 imparts the same rotation to camshaft 5" ascamshaft 5 would be otherwise freely rotatable in hub 6 through thebearing aperture 39. To make contact, drive means 21 are halted and thebraking means 22 are energized. Thus gears 9 and 8, rods 4, and contactdevice 3 are held against rotation. Then, solenoid 64 is de-energized.Biasing means Within solenoid 64 overcomes the bias of spring 65 andmoves actuator shaft 63 inwardly to position II. This inward movement,through the coacting of dog-leg slot 11 and dowel-pin 12, imparts rotarymotion to camshaft 5". Rotation of the camshaft 5", coacting with key37, imparts the same rotation to earn sleeve 33. Rotation of the camsleeve 38 drives the contactors 3.1 outward into contact with se lectedturn 2. By energizing solenoid 64, to impart a reverse rotary motion tocamshaft 5", cam sleeve 33 is returned to its original position.Circular spring 32 urges contactors 31 inwardly withdrawing them fromcontacting engagement with turn 2.

FIGURE 5 shows the annular groove 59 in the contact device 3 andcircular spring 32 resting in recesses 60 of the contactors 31. Key 37is shown within keyway 62 of camshaft 5".

FIGURE 6 illustrates another embodiment of the invention where inertialeffects are used to make and break contact with the helical element. Thedrive means 21 are dlrectly joined to the camshaft 40 which in thisembodiment is shown by way of example to be a three-sided, generallytriangular form in cross-section thus providing three cam surfaces 40a,40b and 400.

Wheels 41 mounted on the contact device 3 rotate on turns 2 of theelement 1 to cause the device 3 to traverse the length thereof. Uponrotation of the camshaft 40', as 13 more evident in FIGURES 7 and 8, thecontact device 3 lags in complementary motion. This is so becausecontact device 3 is not positively joined to the camshaft 40 but spacedtherefrom as shown by the larger triangular opening 44 and resilientlypositioned thereabout by springs 42. Friction and drag of wheels 41retard movement of contact device 3 until forced by the engagement ofcamshaft 46 with the walls of opening 44, FIG. 8. This results in aninertial lag of contact device 3. Because of this lag, springs 43 urgecontactors 31 inward to break contact with turns 2 of the element 1prior to movement of device 3. Springs 43 are mounted to pins 69, fixedin an outer surface of contact device 3, and to pins 70 fixed incontactors 31. Slots 71 are provided in the outer surface of the contactdevice 3 to allow movement of pins 70. Upon cessation of rotary drivefrom drive means 21, springs 42 cause device 3 to properly orient aboutcamshaft 40. This proper orientation causes the cam surface of camshaft40 to slide contactors 31 outward and into contact with a helical turn 2of the element 1.

While 1 have described the principles of my invention in connection withspecific embodiments, it is to be clearly understood that thisdescription is made only by way of example and not as a limitation tothe scope of my invention, as set forth in the objects thereof and inthe accompanying claims.

I claim:

1. In a device having an element disposed in the form of a helix, a camshaft, a contact device disposed within said element and about said camshaft having a contactor adapted to engage by means of said cam shaftsaid element, means to move said contact device axially of said helix,and means to retract said contactor from engagement with said elementduring axial movement of said contact device.

2. In a device according to claim 1, wherein said contact device has aplurality of contactors movable radially for contact engagement withsaid helical element, and said cam shaft includes a plurality of cammingsurfaces, at least one for every contactor.

3. In a device according to claim 2, wherein said camshaft extends alongthe axis of said helix to move said contactors transverse to said axisand within said contact device.

4. In a device according to claim 3, wherein said camshaft comprises acam sleeve positioned within said contact device, said sleeve having acam surface for cooperative engagement with each of said contactors.

5. In a device according to claim 2 wherein said camshaft is triangularin cross-section and extends along the axis of said helix with itsplurality of cam surfaces in cooperative engagement with said pluralityof contactors.

6. In a device according to claim 3, further including actuator shaftmeans having a dog leg for causing rotary displacement of said camshaftto cause said camshaft to move said plurality of contactors radially.

7. In a device according to claim 4, further including actuator shaftmeans having a dog leg for causing rotary displacement of said camsleeve to cause said cam sleeve as a result of the displacement to movesaid contactors radially in a given direction to effect contactingengagement with said helical element, and said actuator shaft means tocause said cam sleeve to cooperate with said retracting means to movesaid contactors radially in a direction opposite to said given directionto disengage contact with said helical element.

8. In a device, according to claim 5, further including drive means forcausing rotary displacement of said camshaft and said contact device tocause said camshaft to move said plurality of contactors radially in agiven direction to effect contacting engagement with said helicalelement, and upon further rotary displacement said camshaft to cooperatewith said contact device and retracting means to move said plurality ofcontactors radially in a direction opposite to said given direction todisengage contact with said helical element.

9. .In a device, according to claim 8, wherein said retracting meansinclude means for causing inertial and rotary displacement of saidcontact device, relative to said camshaft, during movement of saidcontact device axially of said helix.

References Cited UNITED STATES PATENTS 2,658,131 11/1953 Hamacher et a1338-143 2,961,626 11/1960 Moore et a1 338143 3,017,593 1/1962 Emenaker338--143 3,020,497 2/1962 Argentieri et a1. 338143 X 3,020,507 2/1962Johnson 338-143 ROBERT K. SCHAEFER, Primary Examiner.

H. J. HOHAUSER, Assistant Examiner.

